A structural beam used in suspended panel ceilings is usually fabricated from metal. When such a beam is subjected to heat of a fire the beam expands and if the beam is held fast at its ends, the beam will buckle and distort along its length. When there is no provision in the beam for accommodating such thermal expansion in a controlled manner, such beam distortion can result in the dropping of ceiling tiles or panels from the suspended ceiling. Ceiling panels are usually fabricated from fire retardant material. These ceiling panels should therefore be retained in the suspended ceiling as long as possible during a fire to retard the spread of fire.